Introduction
The "Game of Life" is not actually a game - it's more of a mathematical curiosity best described by this quote from the author's website:

Cellular automata were first studied in the mid-1950s by Stanislaw Ulam and John von Neumann. The subject became much more widely known in 1970 when John Conway's Game of Life was described by Martin Gardner in his Scientific American column.

Life is played on an arbitrary-sized grid of square cells. Each cell has two states: "dead" or "alive". The state of every cell changes from one "generation" to the next according to the states of its 8 nearest neighbors: a dead cell becomes alive (a "birth") if it has exactly 3 live neighbors; a live cell dies out if it has less than 2 or more than 3 live neighbors. The ìgameî of Life simply involves starting off with a pattern of live cells and seeing what happens.

Even though the rules for Life are completely deterministic, it is impossible to predict whether an arbitrary starting pattern will die out, or start oscillating, or fill the grid. Life and other CAs (cellular automata) provide a powerful demonstration of how a very simple system can generate extremely complicated results.

The LifeLab application lets you explore the behavior of cellular automata - cells in a grid subject to the above "Life" rules. You can also change the rules, play in 1 dimensional or 2 dimensional space and connect the edges of the playing surface in various ways including torus and Klein bottle.

In Use
LifeLab works in OS X, and OS 8.6/9.x with Carbonlib 1.3 or later. It can be downloaded from www.trevorrow.com and needs no special installation. It comes with a comprehensive help function which also gives references and related websites.

For those who are new to the idea of cellular automata, the gist of it is that the cells represent a population of living organisms - maybe trees or slow moving animals - which can die of either loneliness or overcrowding, but can thrive when they have the right amount of companions. You draw the starting arrangement of cells on the grid with a pencil tool and then use the controls to run the "game" and see the population grow or die out. There are many well-known patterns which evolve in surprising ways, such as gliders, spaceships, guns which fire bullets, and the rabbit and acorn patterns which start small and take over. LifeLab comes with a set of patterns to try out, and more are available for people who pay the shareware fee. The fascination of the subject is to study the behavior of known patterns and perhaps discover new patterns with interesting behavior.

As someone who spent some time exploring a similar but different mathematical curiosity (fractals, including the Mandelbrot set and computer generated plants), I was aware of Life and had seen at least one Life application before. My impression of LifeLab is that, at version 4.2, this is a mature product which has been improved many times to maximize usability for avid students of Life. This version has added functionality, fast algorithms, compatibility with files generated by other programs, and copes well with hardware and OS upgrades. It works well, is easy to use, and I didn't encounter any bugs.

Summary
LifeLab is a full featured application for exploring the behavior of cellular automata. For people who are captivated by Life, the LifeLab application deserves 5 mice and is worth the $20 shareware fee. However, if a 5 mouse review means an essential application that most people will want to use all the time, then this cerebral mathematical curiosity must score less than 5. Despite its limited long-term interest for most people, I would certainly recommend everyone to download it and try it out - it's very thought provoking for anyone with any interest in the environment to see large populations evolve from a small start, or apparently healthy populations doomed to vanish by some quirk of the starting conditions.

Pros

• editable rules
• list of reference books and websites
• more patterns for registered users

Cons

• likely to have a limited audience

Overall Rating

4 out of 5 Mice